This invention relates to vegetable cutters and more particularly relates to an improved impeller for use in a vegetable cutter to urge the vegetables being cut against the blade of the cutting knife.
Several vegetable cutting machines are known in the art. One of these is the french fry cutter, Model GRL manufactured by Urschel Laboratories, Valparaiso, Indiana. The Urschel Model GRL french fry cutter has a hollow, substantially cylindrical drum into which the potatoes to be cut are introduced. The drum has a forward open end through which the potatoes pass. An impeller unit mounted within the drum includes a solid backplate which prevents the potatoes from exiting the drum. The back plate is orthogonal to the cylindrical axis of the drum. A series of impeller blades extend from the backplate and are radially oriented within the drum. The blades extend radially inwardly from adjacent the interior surface of the drum a distance less than the radius of the drum but sufficient to engage a potato in the drum. The impeller unit is mounted within the drum for rotational movement of the impeller blades about an axis coincident with the cylindrical axis of the drum such that the impeller blades sweep the interior surface of the drum, pushing any potatoes which are in the drum before them. An elongate slabbing knife is positioned adjacent the drum with its elongate dimension substantially parallel to the axis of the drum. The cutting edge of the knife extends into the drum. As the impeller blades rotate, they push the potatoes around the interior of the drum and into contact with the slabbing knife, causing a slab to be cut from the potatoes. Once the first slab is cut, a series of circumferential grooves formed on the interior surface of the drum hold the potato in place until it is completely cut into slices. Another series of knife blades is preferably positioned outside the drum to cut the slabs emerging from the drum into individual french fries.
The potatoes are introduced into the drum by sliding them down a chute positioned in front of the drum and allowing them to fall into the open end of the drum. Since the cutting operation is continuous, the impeller blades are constantly rotating around the interior surface of the drum as the potatoes are being fed into the drum. Therefore, as the potatoes enter the drum and drop toward the periphery of the drum, they are abruptly hit by the next blade coming by. The abrupt contact of the flat blade against the potatoes can bruise or fracture the potato, resulting in a bruised or fractured french fry. Such fries detract from the quality of the final product and reduce the economic efficiency of the operation.
The majority of the potatoes utilized in the process will be generally oblong in shape, having a major axis which is longer than a minor axis of the potato. It is desirable that the potato be aligned such that the major axis lies along the longitudinal dimension of the impeller blade when it reaches the slabbing knife so that a longer slice will be cut, resulting in longer french fries. In the conventional apparatus now in use, there is a tendency for some of the potatoes to flip as they enter the drum or to bounce off the backplate and align themselves with the major axis radially oriented to the interior surface of the drum such that the cut is made along the minor dimension of the potato and resulting in short french fries. In the french fry industry, a batch of french fries having a high percentage of short, i.e., approximately less than 3", french fries is considered to be of low quality and commands a lower price than french fries in which the majority of the fries are over 3" long.
It is therefore an object of the present invention to provide an improved impeller for use with vegetable cutters which will gently accept the vegetables from the loading chute into the drum without bruising or fracturing the vegetables.
It is a further object of the invention to provide an improved impeller blade which when used in a french fry cutter will in nearly all cases align the potato so that it is presented to the cutting blade with its longest dimension substantially parallel to the cutting knife to provide a high percentage of long french fries.
It is yet another object of this invention to provide an improved impeller which will permit the vegetable cutter to provide a high quality output product while accepting input raw material at a higher rate than prior art impellers.